I'd be tempted to make it small scale, more Androzani less The End of Time and ooh aren't I brilliant!

No giant Dalek invasions, no farewell tour, no saving the Universe. I'd have 11 sacrifice himself to save a single child, I think that'd sum up Smith's tenure rather well.

See, that feels like 10 sacrificing himself to save Wilf.

No because the Doctor sacrificed himself to save Wilf after saving the Universe/Multiverse/All of time itself...having to save Wilf was a direct result of saving all of reality, or something. Compare that with Androzani where the Doctor's entire motivation throughout the story is just saving Peri.